<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <title>Circles to Rhombuses Spinner</title>
  <style>
    .circles-to-rhombuses-spinner, .circles-to-rhombuses-spinner * {
      box-sizing: border-box;
    }

    .circles-to-rhombuses-spinner {
      height: 15px;
      width: calc( (15px + 15px * 1.125) * 3);
      display: flex;
      align-items: center;
      justify-content: center
    }

    .circles-to-rhombuses-spinner .circle {
      height: 15px;
      width: 15px;
      margin-left: calc(15px * 1.125);
      transform: rotate(45deg);
      border-radius: 10%;
      border: 3px solid #ff1d5e;
      overflow: hidden;
      background: transparent;

      animation: circles-to-rhombuses-animation 1200ms linear infinite;
    }

    .circles-to-rhombuses-spinner .circle:nth-child(1) {
      animation-delay: calc(150ms * 1);
      margin-left: 0
    }

    .circles-to-rhombuses-spinner .circle:nth-child(2) {
      animation-delay: calc(150ms * 2);
    }

    .circles-to-rhombuses-spinner .circle:nth-child(3) {
      animation-delay: calc(150ms * 3);
    }

    @keyframes circles-to-rhombuses-animation {
      0% {
        border-radius: 10%;
      }

      17.5% {
        border-radius: 10%;
      }

      50% {
        border-radius: 100%;
      }


      93.5% {
        border-radius: 10%;
      }

      100% {
        border-radius: 10%;
      }
    }

    @keyframes circles-to-rhombuses-background-animation {
      50% {
        opacity: 0.4;
      }
    }
  </style>
</head>
<body>

<div class="circles-to-rhombuses-spinner">
  <div class="circle"></div>
  <div class="circle"></div>
  <div class="circle"></div>
</div>

</body>
</html>
